1 Field of the Invention
The present invention relates to a novel cycloalkene compound and a recording material which uses the compound as a color former.
2. Prior Art
Color formers, pale or colorless basic dyes, have been used in various recording materials such as pressure sensitive recording materials, heat sensitive recording materials, electrical heat sensitive recording materials, and photo sensitive recording materials. These recording materials are in great demand these days with the development of the information industry.
Typical color formers which have been used for recording materials such as pressure sensitive recording sheets, heat sensitive recording sheets and photo sensitive recording sheets, include phthalide compounds, fluoran compounds, and triphenyl methane compounds. For example, blue-coloring crystal violet lactone is a typical phthalide compound, black-coloring 2-(2-chloroanilino)-6-dibutylaminofluoran is a typical fluoran compound, and blue-coloring leucocrystal violet is a typical triphenyl methane compound.
Recently, computers have been employed widely for the rationalization of clerical works for office automation, or for the rationalization of various works for factory automation. For the input of information for such computers, various optical character readers or optical bar code readers have been developed in recent years.
With the progress of optical character readers or optical bar code readers where near infrared ray such as semi-conductor laser is used as a light source, recording materials suitable for these readers have been demanded Recording materials using previous color formers, however, were unsuitable for these new readers because the color formers had no light absorption in the near infrared region around 700-900 nm. Accordingly, recording images obtained from the previous recording materials were unsuitable for the recording images for the optical character readers or optical bar code readers which use near infrared ray as their light sources